Serotonin levels as a function of age in Aplysia californica.
The neurotransmitter serotonin (5-HT) plays an important role in a number of behaviors in Aplysia californica some of which have been shown to vary with age. We were thus interested in examining the age-dependence of 5-HT in A. californica. Because animals of the same age can have very different weights, and weight alone is reliably known for wild-caught animals, we also examined the variation of 5-HT with weight. Serotonin was measured in the ring and abdominal ganglia combined, in lab-reared animals from 3 to 12 months post-hatch across a wide weight range. Serotonin increased rapidly from 4 to 6 months, and more slowly from 6 to 13 months. Serotonin scaled by soluble ganglion protein increased from 3 to 6-7 months, reached a maximum, and then decreased again. Serotonin, but not scaled 5-HT, increased significantly with weight across the whole weight range. Animals of the same weight, but different ages, had different 5-HT levels, as did young animals of the same age but different weight. Serotonin varied significantly with both age and weight, with the age-dependence being the more significant.
Flinn
J M
JM
Department of Psychology, George Mason University, Fairfax, VA 22030, USA.
Hong
C
C
Holt
R
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Chandhoke
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D000375:Aging / Q000502:physiology*; D000818:Animals; D001048:Aplysia / Q000254:growth & development*; D001835:Body Weight; D002851:Chromatography, High Pressure Liquid; D017952:Ganglia, Invertebrate / Q000737:chemistry; D012701:Serotonin / Q000032:analysis*
D012701:Serotonin